In 2013, HEPAP was asked to convene a panel to evaluate research priorities in the context of anticipated developments in the field globally in the next 20 years. Recommendations were to be made on the basis of three funding scenarios for high-energy physics:
A constant funding level for the next three years followed by an annual 2% increase, relative to the FY2013 budget
A constant funding level for the next three years followed by an annual 3% increase, relative to the proposed FY2014 budget
An unconstrained budget
In May 2014, the first P5 report since 2008 was released. The 2014 report identified five "science drivers"—goals intended to inform funding priorities—drawn from a year-long discussion within the particle physics community. These science drivers are:
Use of the Higgs boson as a tool for further inquiry
Exploration of new particles, interactions, and physics principles
Recommendations
In pursuit of the five science drivers, the 2014 report identified three "high priority large category" projects meriting significant investment in the FY2014–2023 period, regardless of the broader funding situation: the High Luminosity Large Hadron Collider ; the International Linear Collider ; and the Long Baseline Neutrino Facility. In addition to these large projects, the report identified numerous smaller projects with potential for near-term return on investment, including the Mu2e experiment, second- and third-generation dark matter experiments, particle-physics components of the Large Synoptic Survey Telescope, cosmic microwave background experiments, and a number of small neutrino experiments. The report made several recommendations for significant shifts in priority, namely:
An increase in the proportion of the high-energy physics budget devoted to construction of new facilities, from 15% to 20%-25%
An expansion in scope of the Long Baseline Neutrino Experiment to a major international collaboration, including redirection of resources from other R&D projects to the development of higher powered proton beams for the neutrino facility
Increased funding for second-generation dark matter detection experiments
The panel stressed that the most conservative of the funding scenarios considered would endanger the ability of the U.S. to host a major particle physics project while maintaining the necessary supporting elements.
